Early detection and resection of cancer is the most effective in the treatment of solid cancer. Development of a new cancer detection method is expected to become a breakthrough to solve various problems for early detection. It has been reported that there is the specific odors of cancer by using bio olfaction such as dogs, and it has been recognized that there is the odors of cancer. Cancer cells acquire malignant traits as a result of metabolic changes originating from genetic mutation. The cancer specific odorous substances may be considered to be the end products of their metabolic changes. Omics researches such as genomics, proteomics, and metabolomics have been extensively performed to comprehensively analyze changes in DNA, RNA, protein, metabolism and its products specific to cancer for the purpose of developing a new cancer detection marker. It is thought that the research on the odor of cancer is also on the line of omics research. It is difficult to identify cancer-specific odorants buried in various environmental substances. However, it is expected that human will be able to acquire the technology, from the fact that they can be recognized by biological olfaction. We are continuing the research with the dream that identification of the odorous substances as a new cancer detection marker and sensor development for it will lead to the happiness of colleagues in the world.